"Make a sound, you little bastard, tell me if you want to ejaculate." The protagonist trains a seemingly innocent but actually ...

"Make a sound, you little bastard, tell me if you want to ejaculate." The protagonist trains a seemingly innocent but actually eccentric junior. The junior immediately applies what she's learned, directly reversing the training of the male lead. She uses her feet and hands to rub his penis until he ejaculates, and even makes him call her "Mommy." After being violently fucked, he ejaculates his thick semen directly into the junior's mouth.